"An erect annual or perennial herb with branching habit to about 1m high. Leaves are deeply divided into three toothed lobes, with the terminal lobe larger than the other two. Individual flowers are yellow but are tiny and held in dense terminal clusters in a widely branching flowering head. Each flower cluster has four or five short, broad, white 'petals' but these do not persist for very long. The seeds are black, about 1 cm long, with 2 or 3 barbed awns at the
tip. In French Polynesia, American Samoa, and many other places in the Pacific, there is a variety B. pilosa minor, which has white flowers. In French Polynesia the variety B. pilosa pilosa also occurs." (Waterhouse and Norris, 1987; pp. 274-276)

Habitat/ecology: "Cobbler's pegs or beggar's ticks is a prolific ephemeral herb... It occurs as a major weed of vegetables and other crops; it is common in pastures, plantations, along roadsides and on wasteland throughout the region. It thrives best in full sun, where the soil is relatively dry and infertile." (Swarbrick, 1997) It forms a dense ground cover that prevents regeneration of other species.

Grows well up to 1,300 m, to over 2,000 m in Papua New Guinea. In Hawaii, "widespread in disturbed areas" (Wagner et al., 1999; pp. 279-281). In Fiji, "naturalized along trails and roads, in cultivated areas, and on waste land from near sea level to an elevation of about 900 m" (Smith, 1991; pp. 281-282). In New Guinea, "a weed of cultivation, roadsides, forest clearings, plantations and overgrazed pasture. From low altitudes to over 2000 m" (Henty & Pritchard, 1975; p. 64). In Tonga, "a waste-area weed" (Yuncker, 1959; p. 269). Moist uplands in the Galápagos Islands (McMullen, 1999; p. 259).

Propagation: Seeds, which attach to clothing or animal's fur or feathers. Also dispersed by water.
"Single plants produce up to 6000 seeds, many of which germinate readily,
permitting three or four generations a year in some regions. Sone seeds
remain viable in the soil for at least 5 years. When herbicides have
eradicated perennial grasses this weed often becomes dominant"
(Waterhouse, 1994; p. 28).

Native range: Temperate and tropical America, but introduced early to the Pacific and parts of Asia.

Physical: "Germination is prevented by mulches if they are thick enough and left undisturbed. It is susceptible to hand weeding, chipping and cultivation. Unpalatable to stock. As it prefers full sunlight it can be controlled by competition from leafy crops, such as cassava and sweet potato. Tolerates dry air and soil conditions" (Swarbrick, 1997).
"Grazed by livestock"
(Motooka et al., 2003).